A spatially multiplexed autostereoscopic display system typically has either a lenticular screen or a parallax barrier. The concept of lenticular screens and parallax barrier type approaches to spatially multiplexed autostereoscopic images are over 100 years old. Each of these approaches allows for each eye to only see a portion of the image, which is particular to either the left or right eye frame sequential stereo image data.
FIG. 1 is a schematic diagram 100 showing an example of a parallax-barrier type display. A parallax barrier 102 is a device placed in front of an image source 104, such as a liquid crystal display (LCD), to allow it to show a stereoscopic image without the need for the viewer to wear 3D glasses. Placed in front of the normal LCD, the parallax barrier 102 includes a layer of material with a series of precision slits, allowing each of the left eye 106 and right eye 108 to see a different set of pixels, thus creating a sense of depth through parallax. A disadvantage of the technology is that the viewer generally has to be positioned in a well-defined location to experience the 3D effect. Another disadvantage to parallax-barrier type displays is that the effective horizontal pixel count viewable for each eye is reduced by one-half.
FIG. 2 is a schematic diagram 200 showing an example of a lenticular lens type display. A lenticular lens 202 is an array of cylindrical lenses, designed so that when viewed from slightly different angles, only certain pixels are visible. FIG. 2 shows how when a lenticular lens array 202 is applied to a pixilated screen 204, it can produce an autostereoscopic view, providing alternate imagery for the left eye 206 and right eye 208. Similar to the barrier approach, lenslet systems require the viewer to accurately position his or her head; though unlike barrier approaches, little light is lost, yielding higher efficiency.
Unfortunately, both the parallax barrier and lenticular lens array technologies have fabrication procedures that demand precision alignment of the optic to the TFT and color filter planes. Accordingly, what is needed in the art is a spatially multiplexed autostereoscopic display technique that provides the autostereoscopic 3D visual effect desired, but does not suffer from the deficiencies of conventional approaches.